Multiple expansion sand screen system and method

ABSTRACT

In one embodiment, a wellbore completion method includes disposing an expandable screen assembly into a wellbore, in which the expandable screen assembly includes a base pipe, an intermediate expansion system, and a screen element. The method further includes radially expanding the base pipe and radially expanding the intermediate expansion system after radially expanding the base pipe.

RELATED APPLICATIONS

This application claims the benefit of Ser. No. 60/532,934, entitled“Expandable Sand Screen Utilizing Multiple Expansion System,” filedprovisionally on Dec. 29, 2003.

TECHNICAL FIELD OF THE INVENTION

This invention relates generally to the field of wellbore completionand, more particularly, to a multiple expansion sand screen system andmethod.

BACKGROUND OF THE INVENTION

Sand control is important during completion and subsequent production ofa wellbore that is in hydraulic communication with Earth formationssusceptible to production of solid materials from the formation. Suchformations are known in the art as “unconsolidated” and, if notprotected with suitable wellbore equipment, may produce solid materialsof a character and quantity so as to damage the wellbore, or at leastreduce its capacity to produce oil and gas from the formation. Devicesknown in the art as “sand screens” are typically used to protect suchunconsolidated formations. Sand screens include a structural member,called a “base pipe”, having apertures therein to maintain themechanical integrity of the sand screen (meaning to provide mechanicalsupport for the screen. A “filter layer” is typically disposed outsidethe base pipe. Many different types of filter layer are used, including,for example, wound wire and mesh screen.

More recently, radially plastically deformable sand screens, called“expandable sand screens” have been used in some wellbores to increaseproductivity of wellbores completed in unconsolidated Earth formations.A principal reason for the use of expandable sand screens is tomechanically support the unconsolidated formation prior to initiatingfluid production. By supporting the formation prior to initiatingproduction, it is possible to reduce loss of formation permeability dueto movement of solid materials against the screen during fluidproduction. A conventional (non-expandable) sand screen must necessarilyhave an external diameter smaller than the drilled out diameter of thewellbore (“open hole”) prior to insertion of the sand screen, in orderfor the screen to fit in the wellbore. The smaller screen diameterresults in an annular space between the outer surface of the screen andthe wall of the wellbore, which may become filled with formation solidsmoved from the formation during fluid production. Expandable sandscreens are intended to provide a way to close the annular space priorto beginning fluid production, and thus prevent movement of formationsolids. Expandable sand screens are run into the wellbore in anunexpanded state, wherein the external diameter of the screen is lessthan the drilled out diameter of the wellbore. After insertion, thescreen is expanded using one or more types of expansion tools,preferably to cause the screen to be placed into firm contact with thewellbore wall.

During the expansion of expandable sand screens, it is advantageous topush the sand screen outward to an extent so that it “conforms” to, andapplies pressure to, the wellbore wall in order to hold the sand inplace and increase oil and/or gas flow into the wellbore. Many wellboresmay include sections where the actual diameter of the wellbore exceedsthe drilled out diameter (drill bit diameter) due to washout or othercause. In such sections, it maybe necessary to expand a screen to 35 or40 percent greater than its unexpended diameter in order to place thescreen in form contact with the wall of the wellbore.

One problem with expandable screens known in the art is that they aredifficult to expand more than about 30 to 35 percent because the basepipes made out of carbon steel or stainless steel begin to fail. As aresult, these screens may often not be expanded enough to apply the highcontact pressures needed to hold the sand in place in enlargedwellbores, thus resulting in failure of the sand screen or inadequateproduction. Conversely, if expanded to the degree necessary to provide asuitable amount of contact pressure, the base pipe may be weakened to anextent so as to have very little resistance to crushing under externalpressure, thus leaving the wellbore susceptible to failure.

SUMMARY OF THE INVENTION

It is desirable to have an expandable sand screen that can be made toconform to the wall of a wellbore, even if it is necessary to expand thescreen to 35 percent or more beyond the unexpanded diameter of thescreen, while maintaining sufficient mechanical integrity to resistfailure of the screen and consequent loss of the wellbore.

In one embodiment, a wellbore completion method includes disposing anexpandable screen assembly into a wellbore, in which the expandablescreen assembly includes a base pipe, an intermediate expansion system,and a screen element. The method further includes radially expanding thebase pipe and radially expanding the intermediate expansion system afterradially expanding the base pipe.

Embodiments of the invention may provide a number of technicaladvantages. In one embodiment, an expandable screen possesses highcollapse strength (e.g., 1000 to 3000 psi) due to the strong base pipe.Such a screen may also be quickly and reliably expanded with fixed orcompliant cone expanders without limited expansion like prior fixed-coneexpansion screens.

Other technical advantages are readily apparent to one skilled in theart from the following figures, descriptions, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are cross-sectional elevation views illustrating awellbore completion method in accordance with one embodiment of thepresent invention.

DETAILED DESCRIPTION

FIGS. 1 and 2 are cross-sectional elevation views illustrating awellbore completion method in accordance with one embodiment of thepresent invention. Referring first to FIG. 1, a wellbore completionsystem 100 is utilized in completing a wellbore 101 drilled within aformation 102. Wellbore 101 may be drilled using any suitable drillingtechniques and may have any suitable diameter, length, and direction.Formation 102 may be any suitable geological formation; however, thepresent invention is particularly suitable for unconsolidatedformations, such as sandstone.

Holding the sand or other particles from formation 102 in place duringthe completion process is important for effective oil and/or gas flowinto wellbore 101. Thus, expandable sand screens are sometimes utilizedto hold the sand in place. A major problem with prior expandable sandscreens is that they are difficult to expand more than about 30-35%before the base pipes from which they are made begin to fail. Thus,these prior screens may often not be expanded enough to apply highcontact pressures to hold the sand in place.

Therefore, according to the teachings of one embodiment of theinvention, an expandable screen assembly 104 is utilized that includes,in the illustrated embodiment, a base pipe 106, an intermediateexpansion system 108, and a screen element 110. Among other things,expandable screen assembly 104 possesses high collapse strength due tothe strength of base pipe 106 in addition to facilitating quick andreliable expansion without limited expansion.

Base pipe 106 may be any suitable pipe of any suitable size andconfiguration and may be formed from any suitable material, includingwithout limitation, carbon steel and stainless steel. Base pipe 106includes any suitable size and number of apertures formed therein toenable flow of fluid from formation 102 into the wellbore 101. Base pipe106 may also have any suitable length and may be formed from one or moresections. Base pipe 106 may be disposed in wellbore 101 by any suitablemethod, such as the utilization of a suitable work string 112. Asdescribed in further detail below, any suitable method may be utilizedto expand base pipe 106, such as a cone expander 114 or other suitableexpander element. The expansion of base pipe 106 also expandsintermediate expansion system 108 and screen element 110.

Intermediate expansion system 108 is disposed around the outside of basepipe 106 and may or may not couple directly to base pipe 106.Intermediate expansion system 108 is formed from one or more componentsthat are operable to radially expand via an actuation system 116. Radialexpansion of intermediate expansion system 108 causes radial expansionof screen element 110. Intermediate expansion system 108 may be anysuitable material formed from one or more components that expand inresponse to actuation of actuation system 116.

Actuation system 116 may be any suitable actuation system that functionsto radially expand intermediate expansion system 108. For example,actuation system 116 may be a chemical expansion system, a thermalexpansion system, an electrical expansion system, a mechanical expansionsystem, or any other suitable actuation system.

In a chemical expansion system embodiment, spheres of any suitablematerial that swell when immersed in a suitable chemical may beutilized. The chemical may be pumped down base pipe 106 and through theapertures formed in base pipe 106 in any suitable manner in order tocontact the swellable spheres. For example, a suitable rubber orelastomer that swells in the presence of a liquid such as crude oil maybe utilized. As another example, compressible elastic spheres that arecoated with a suitable material that holds them in compression until achemical is utilized to dissolve or degrade this particular coating maybe utilized. In this embodiment, the spheres elastically expand outwardwhen the confining pressure produced by the coating is removed. Othersuitable chemical expansion systems are contemplated by the presentinvention.

In a thermal expansion system embodiment, any suitable materials thatexpand or swell when they are heated may be utilized. For example,elastic spring-like materials, bimetallic springs that bend when theyare heated, or shape memory alloys that transform into a different shapewhen heated may be utilized. Other suitable thermal expansion systemsare contemplated by the present invention.

In an electrical actuation system embodiment, suitable materials thatchange dimensions when subjected to electric current, such aspiezoelectric materials, may be utilized. Other suitable electricalexpansion systems are contemplated by the present invention.

In a mechanical expansion system embodiment, a plurality of spheres orother particles that push radially outward and expand screen element 110when subjected to axial compression from a piston or other suitableelement may be utilized. Other suitable mechanical expansion systems arecontemplated by the present invention.

Screen element 110 may be any suitable screen of any suitable size andconfiguration and may be formed from any suitable material. For example,screen element 110 may be formed from a suitable carbon steel andinclude a fine screen or coarse screen (or both) inside of a suitablesleeve (sometimes referred to as a “shroud”) having suitable aperturesformed therein. Screen element 110 may also have any suitable length andmay be formed from one or more sections. Screen element 110 is disposedaround the outside of intermediate expansion system 108 and may or maynot directly couple to intermediate expansion system 108. As describedin greater detail below, after expansion of base pipe 106 andintermediate expansion system 108, screen element 110 engages andapplies a force to the wall of wellbore 101.

System 100 may also include a pump 118 operable to dispose a completionfluid 120 into an annular space 122 between the wall of wellbore 101 andscreen element 110. Any suitable pump is contemplated by the presentinvention. Completion fluid 120 may be any suitable completion fluid.

In operation of one embodiment of the invention, and with reference toFIGS. 1 and 2, wellbore 101 is first drilled by any suitable methodwithin formation 102 and the upper portion thereof may be cased with acasing (not explicitly illustrated). A suitable liner hanger (notexplicitly illustrated) is utilized to position expandable screenassembly 104 within wellbore 101. Work string 112 with expander 114coupled thereto is then run-in-hole and completion fluid 120 iscirculated down into wellbore 101. Completion fluid 120 fills annularspace 122.

Work string 112 is then utilized to apply weight to expander 114, whichtranslates downward and starts radially expanding base pipe 106.Expander 114 plastically deforms base pipe 106. As base pipe 106 isradially expanded outwards towards the wall of wellbore 101,intermediate expansion system 108 and screen element 110 may also beexpanded radially.

After base pipe 106 has been expanded as desired, then intermediateexpansion system 108 is expanded via actuation system 116. Intermediateexpansion system 108 expands screen element 110 further towards the wallof wellbore 101 so that it applies a force to the wall of wellbore 101.In other embodiments, intermediate expansion system 108 may be radiallyexpanded by actuation system 116 before base pipe 106 is expanded. Anysuitable amount of expansion of base pipe 106, intermediate expansionsystem 108, and screen element is contemplated by the present invention.

Thus, system 100 includes expandable screen assembly 104 that increasesthe overall expansion of screen element 110 to ensure that screenelement 110 contacts the wall of wellbore 101 and exert adequate forcethereto for sand control and efficient production from wellbore 101.

Although embodiments of the invention and their advantages are describedin detail, a person of ordinary skill in the art could make variousalterations, additions, and omissions without departing from the spiritand scope of the present invention as defined by the appended claims.

1. A wellbore completion method, comprising: disposing an expandablescreen assembly into a wellbore, the expandable screen assemblycomprising a base pipe, an intermediate expansion system disposedoutside the base pipe, and a screen element disposed outside theintermediate expansion system; radially expanding the base pipe; andradially expanding the intermediate expansion system after radiallyexpanding the base pipe.
 2. The method of claim 1, further comprisingdisposing a completion fluid into an annular space between a wall of thewellbore and the expandable screen assembly.
 3. The method of claim 1,wherein radially expanding the intermediate expansion system compriseschemically expanding.
 4. The method of claim 1, wherein radiallyexpanding the intermediate expansion system comprises thermallyexpanding.
 5. The method of claim 1, wherein radially expanding theintermediate expansion system comprises electrically expanding.
 6. Themethod of claim 1, wherein radially expanding the intermediate expansionsystem comprises mechanically expanding.
 7. A wellbore completionsystem, comprising: an expandable screen assembly configured to bedisposed into a wellbore, the expandable screen assembly comprising abase pipe, an intermediate expansion system outside of the base pipe,and a screen element outside of the intermediate expansion system; anexpander operable to radially expand the base pipe; and an actuationsystem operable to radially expand the intermediate expansion system. 8.The system of claim 7, further comprising a pump operable to dispose acompletion fluid into an annular space between a wall of the wellboreand the expandable screen assembly.
 9. The system of claim 7, whereinthe expander comprises a cone expander.
 10. The system of claim 7,wherein the actuation system comprises a chemical expansion system. 11.The system of claim 7, wherein the actuation system comprises a thermalexpansion system.
 12. The system of claim 7, wherein the actuationsystem comprises a electrical expansion system.
 13. The system of claim7, wherein the actuation system comprises a mechanical expansion system.14. The system of claim 7, wherein the actuation system comprises aplurality of expandable spheres.
 15. A wellbore completion method,comprising: disposing an expandable screen assembly into a wellbore, theexpandable screen assembly comprising a base pipe, an intermediateexpansion system, and a screen element; radially expanding theintermediate expansion system; and radially expanding the base pipeafter radially expanding the intermediate expansion system.
 16. Themethod of claim 1.5, further comprising disposing a completion fluidinto an annular space between a wall of the wellbore and the expandablescreen assembly.
 17. The method of claim 15, wherein radially expandingthe intermediate expansion system comprises chemically expanding. 18.The method of claim 15,, wherein radially expanding the intermediateexpansion system comprises thermally expanding.
 19. The method of claim15, wherein radially expanding the intermediate expansion systemcomprises electrically expanding.
 20. The method of claim 15, whereinradially expanding the intermediate expansion system comprisesmechanically expanding.
 21. An expandable screen assembly, comprising: abase pipe; an intermediate expansion system outside of the base pipe; anactuation system operable to radially expand the intermediate expansionsystem; and a screen element outside of the intermediate expansionsystem.
 22. The system of claim 21, wherein the actuation systemcomprises a chemical expansion system.
 23. The system of claim 21,wherein the actuation system comprises a thermal expansion system. 24.The system of claim 21, wherein the actuation system comprises aelectrical expansion system.
 25. The system of claim 21, wherein theactuation system comprises a mechanical expansion system.
 26. The systemof claim 21, wherein the actuation system comprises a plurality ofexpandable spheres.